RWBY : Monster Inside Me
by Yamiya Evans
Summary: Ruby is stuck between her secret and her safety of her friends. In order to prevent the same tragedy, she has no choice but to isolate herself. First fanfic. Please excuse me for my bad English. Implying a bit of strawberry but mainly Yang and Ruby.
1. Luna

Chapter 1 : Luna

Mission goes on as usual. Team RWBY was assigned to investigate the Snowy Forest. Locals claimed that Beowolves grew vicious. Thus, demanding that the Grim has to be obliterate immediately.

The forest is strangely silent. No sign of Grim passed. Ruby look around to find anything that looks like a Grim. Turns out there's nothing and this made Weiss angry,"Where the heck is the Beowolves?! Are you sure they gave us a real information?"

"Oh, shut up, princess! You're not the only one pissed off here!"groaned Yang. Ruby and Blake ignore them and keep on looking. Blake tries to sense the Grim with her 'sixth sense' but no luck. Ruby, in other hand, stood in the middle of the clearing, watching the moon. She mutters,"Full moon tonight..."

"Did you say something?" asks the Fauna. Surprised, Ruby look at her and shook her head. Ruby continue to walk deeper, readying Crescent Rose if there's any threat. Yang and Weiss have ended their childish fight if it wasn't for Blake. She keep on walking, but to no avail, there's nothing.

"It's clear. No sign of the wolves," she said, informing her team mates. Yang and Weiss release an exasperated sigh. Blake just shook her head regarding their two team mates. She look at Ruby, who watches the moon again. Staring deeply into the moon, Ruby's eyes change dramatically yellow and wilder, more like an animal.

The Fauna realizes this hold her shoulder and startled. Her eyes returns to silver. Cold sweat runs through her cheeks. "Is something the matter?"

"It's nothing, really. We should head back," she said. Ruby release a relief sigh. She's lucky enough for hiding it. Another quick glance on the moon, she whisper, 'Luna...'

* * *

Back at their dorm in Beacon, Blake busied herself with her book, Weiss is working with her assignment, Yang, well, snoring in her sleep. And Ruby, she keep on watching the clock. It's half past eleven. She gets up and grab her cloak. Before she could open the door, Weiss asks,"Where're you going at this time?"

"Just...taking some fresh air. I'll be back later." The hallway is awfully quiet tonight. Ruby silently crept to the entrance, careful enough not to wake anyone. She manage to get out without waking anybody. She watches the moon. It has yet midnight but she can feel it. It tries to escape. Thus, she need to let it go.

"Luna, I'll be going out again. Watch over 'us'," In the full moon, a howl of agony soon heard from a distance. A dark figure crawls in the shadows, howling in sadness.


	2. Rage and Awkwardness

Chapter 2 : Rage and Awkwardness

"Weiss, have you seen Ruby?" Yang asks. She hasn't seen her sister anywhere. Weiss, dumbfounded, shook her head. Even Blake doesn't know where the girl is. Suddenly, they heard a commotion outside their dorm. Yang left the room to check it out, followed by Blake and Weiss.

The trio push through the crowd to see what happened. On the floor, they see Ruby sleeping in a weird posture. Curled up in her red cloak, she keep on sleeping, not realizing what happen to her surroundings. "RUBY?!"

The girl in red slowly open her eyes and sees a crowd of students surrounded her. She then saw her team mates among the crowd. What...? She watch where she's sleeping. Her face burning red in embarrassment. She quickly stood up on her feet and cover her face with her hood. Some of the students giggled. Yang, Blake and Weiss dismissed the crowd before Professor Glynda passing the hallway.

"What are you doing, sleeping at the hallway?!" Yang screeched. They need to get ready before class start. Ruby keep on drying her hair, ignoring her sister's question. "Ruby, are you listening to me?"

Ruby wear her boots, still ignoring the question, although she's getting annoyed. "Ruby, can't you just..." Wrong step...

"WOULD YOU JUST SHUT UP?! YOU'RE SO ANNOYING!" Ruby suddenly burst in anger and lashes on Yang. Yang, Weiss and Blake are shocked. Ruby never say her sister annoying nor shouting like that. The girl in red realizes what she did back off and leave the room. The trio stood there, watching the girl left.

* * *

Class has ended and Yang decided to confront her sister. She's been wondering what's wrong with her. The only place she could ever think of is the academy's garden. At the garden, she saw a red figure sitting on a bench. 'It must be Ruby...'

Yang walk towards her but she stepped on twig, making a cracking sound. Startled by it, Ruby take a quick glance on the blonde, gets up and leave. "Ruby, wait!" Yang called out but she's too far. She immediately chase after her.

Ruby try to catch her breath when suddenly she feel someone touch her shoulder. She turn around and sees Blake and Weiss before her. Few seconds later, Yang came and catch her breath. In her mind, she wondered what would they ask her. She immediately apologize,"Yang, whatever you gonna say, I'm sorry for shouting at you. I-I didn't mean to, I swear!"

Ruby tries to escape but Blake blocks her. Weiss and Yang look at her with a worried looks. The huntress begin to trembles. She feel a sudden rage inside her. "Ruby, are you okay? You look...weird today," said Weiss in a soft tone.

"Weird? No I'm not! I feel normal! Ahahaha..."she fail to convince her friends. She clench her hand into fist. Ruby begin to slowly walk away. However, Blake is in her way. Her rage grew larger and suddenly, a tree behind the trio was cut in half. As the three of them watch what happened, Ruby realizes her right hand becomes a claw. She hide it inside her cloak. Slowly, she run into Emerald Forest. Yang saw where she's going, giving a chase.

Weiss and Blake still wondering what and how it happened.


	3. The Scar

Chapter 3 : The Scar

After leaving her friends, Ruby ran deeper into Emerald Forest to find peace. Somehow, she enraged and cut down a tree with her claws. Lucky for her, no one realizes it. Her right hand has returned to normal, although her sleeve have torn. She lean on a tree trunk, trying to catch her breath.

From afar, she heard Yang calling out her name. Afraid of what would she say, Ruby climb on a tree and sit on the branch. Right after she climbed, Yang is underneath her. Not knowing where the girl in red is, she keep on calling her and walk deeper into the forest. ' I'm sorry, sis...'

She leap from branch to branch, tree to tree. Careful enough not to fall, she saw an Alpha Beowolf near a stream. She feel a sudden urge to kill. She left Crescent Rose back at Beacon. She bite her thumb and pounce on the Alpha.

* * *

Weiss and Blake waited outside the Emerald Forest. They heard a loud roar from a distance. Sweat begin to trail on their skin. A moment later, they saw Yang running towards them. There's no sign of Ruby. "Yang, did you found her?" Weiss ask in a worried tone. Yang shook.

Another roar is heard. Weiss begin to have doubts. Blake remains emotionless, Yang started to get worried. Where's Ruby?

On the other hand, Ruby is taking a drink at the stream. Battling the Alpha without Crescent Rose is tiring. The Alpha bit her neck, leaving a faint scar. Sun started to set in the West. Ruby knows that it's time for her to return.

* * *

Yang is waiting for her little sister at her dorm. Since this evening, the blonde hasn't seen Ruby at the academy. Out of boredom, she decided to take a walk. For the past few minutes, she's been asking the students of Ruby's whereabouts. Unfortunately, all she receive is 'no'.

Yang exits the academy and head to the forest again, hoping to find Ruby. As she reaches the border, she sees a silhouette of a person walking towards her. She tries to focus her sight on the figure. It was Ruby. Feeling delighted, Yang immediately ran towards her sister. "My god, Ruby! What happened to you?! You're a mess!"

Seeing the girl in red in exhaustion, Yang wouldn't want to lecture her sister. Ruby started to lose consciousness and fell forward but caught by Yang. The blonde's heart started to break. Carrying her in bridal style, Yang brings her to her dorm, only to find Blake and Weiss waiting. Weiss is the one who overreacting too much,"Yang, what happened to Ruby?!"

"Calm down, princess. More importantly, she need to be treated." Both of them nod. Yang set her sister on her bed. Weiss take of her cloak and shocked to find a scar on her neck. Yang and Blake too shocked to see the scar. The scar's big enough to kill her. Their suspicion on Ruby grew. 'Ruby, what are you keeping from us...?"


	4. Suspicion and Doubts

Chapter 4 : Suspicion and Doubts

Regarding the scar, the trio started to suspect that Ruby is hiding something. Not to mention about her sudden change in behavior. Plus, she disappear every full moon. As her sister, Yang has no choice but to spy on her sister. Blake and Weiss will try to cover her absence.

Awake from her deep slumber, the first thing she do is visiting Headmaster Ozpin. Ruby didn't realize she was followed, close the door. Yang quietly lean her ear on the door, trying to hear their conversation.

Ruby sit on the chair, facing Ozpin. The man still busied himself wit hhis paper works. After a final check, he keep the papers inside his drawer and face Ruby.

"How do you feel today, Ruby?"

"Fine, although feel a bit sore..." She hold her neck, a pang of pain hit her, causing her to whimper. She try to ignore the pain. Headmaster Ozpin hand her some painkillers, which she swallow it whole.

"If you keep this up, you'll end up..."

"Dying? I know," she interrupts. A pang of guilt coursing her mind, thinking that she offended her sister. Ozpin sigh.

"You don't have much time. The more you wait, the more chances your life will perish," he say in a worried tone. This time, Ruby sigh.

* * *

Ruby is...dying? Judging from her frown, she doesn't like what she heard. Her sister's dying and she doesn't know about it? Tears fall down to the floor. Yang never cry before but when she does, it's hard for her to stop. She cover her mouth with her hand. She silently cry outside the headmaster's office.

Yang heard a clicking sound from the door. Lucky for her, the door opens outwards. "Sometimes I feel sorry for you, Ruby. Such a young age to be risked to death. Aren't you afraid?" Professor Ozpin's voice is heard.

"If it is for my friends safety, I don't mind death as I will die myself," the huntress said. Yang cried again as she heard what her sister said. Ruby's footsteps begin to distant away from her. The blonde enters the nearest bathroom and cried till the fullest. She doubted her sister too much, not noticing that she's in a brink of death.

* * *

Yang couldn't sleep nor close her eyes. She remain awake even though the clock strikes 12 midnight. She still thinking of what she heard that morning. She has yet tell Blake or Weiss but she's sure they won't be happy either.

Ruby is next to her. She's the one who demanded her to sleep with her tonight. Seeing the small figure, her heart is broken. Thinking that her sister will die anytime, she silently hug her sister while she cry.

That night, Yang pull her sister into a tight embrace, afraid that she'll lose her in her sleep. Finally, she manage to put herself into deep slumber, still embracing the small, red figure in her bosom.


	5. Insanity

Chapter 5 : Insanity

Yang woke up with blood shot eyes, probably because of crying to much or didn't get enough sleep. Ruby left before her. She still thinking whether to tell the other two or not but for now, she'll keep it as a secret.

The blonde haven't cried so much since her parents funeral. After Ruby was adopted by Crow, both of them grew attach to each other and started to call her 'sis'.

It's ten o'clock in the morning and Yang has yet to get ready. Blake must be furious if she's not around. Putting on her boots, she quickly left her dorm.

As she about to close the door, Yang notices Ruby at the end of the hallway, staring at a painting. Curious, she head towards the huntress and greet her,"Hey, sis. Watcha doin'?"

"Nothing. Just looking at this painting," she answered, barely hear her voice. Yang started to have doubts. Ruby has no interest in anything except for sweets and and weapons. She look at the painting, a woman in white dress descend from the moon."Since when you interested in art?"

"Just now. I find this quite fascinating and beautiful. Don't you think?" She keep on staring at the painting, making Yang uncomfortable. Still, she nod. A small smile formed in the huntress's face. She look at her sister and excuse herself,"I'm sorry for taking your time. By the way, Blake is looking for you. Excuse me."

As Ruby walk pass her sister, Yang felt a strange sensation coming from her. Something tells her she's in trouble and begging for help. She take a quick glance at her sister, seeing that she's holding her neck. Cold sweat trail on her skin.

* * *

Team RWBY was assigned to obliterate Grimms which have reached the border of Emerald forest. By killing the Alpha, the smaller ones will leave. So far, there's no sign of the Alpha except for the goons. So they decided to split up.

Before they ever split up, Ruby's hair started to rise, more like a cat. Yang suggested they should split up into pairs but Ruby insisted on going alone. After few arguments and judgement, Ruby end up going alone while the other three go as a team.

Yang started to get worried by time to time. Weiss feel the same as well but manage to hide it. Blake remain emotionless, although she feel a slight worry. On the other side, Ruby's hair keep on rising. She knew that she's getting closer to the Alpha. She readying Crescent Rose , even though she's going to use brute force.

The bushes near her rustles. Her hair rise madly. Found you... She cut her palm with her scythe. As the Alpha about to pounce, she claw it in the gut.

A roar echoed in the forest. Yang was about to run off to find Ruby but Blake calm her down. Weiss suddenly scream when an Alpha jumped out from the bushes with its gut clawed. The trio readying their weapons and was about to attack.

Ruby jumped out from a tree and strike the Alpha with her scythe. The Grimm gave out a load roar, hurting their ears but Ruby doesn't mind it. She keep on striking it even though its already dead. Her eyes shows a large amount of insanity, mindlessly cut the Grimm. "Ruby, that's enough!"

The huntress slowly regain her sanity. The creature's blood dirtied her face and clothes as well her weapon. She breath hardly, trying to catch her breath. Her hair has stopped rising. Seeing a dead Grimm before her and the blood on her, she suddenly scream.

* * *

After few hours of cleaning herself, Headmaster Ozpin requested her to visit him in his office. Ms. Glynda is in the room too. After greeting both of them, Ozpin when straight to his question, "I heard that you mindlessly kill a Grimm. Is it true?"

Ruby nod. She wouldn't dare to look at either of them, she didn't deny the fact that she went insane but afraid of their reaction. Ms. Glynda hold her shoulder, calming her down."You realize that the more insane you are, the more your life will be drain."

"Like I said, I don't mind death. What's more important is my friends safety."

"Will they ever accept it? Will it ever lead them to a happy ending if you gone?" Ruby look down. She slowly shook her head. She started to think of her sister, Yang. She had no one else except for herself. Yang won't be happy about it.

Outside the room, Yang silently cry after she heard everything. She doesn't want to lose her, just like she lose her parents.


	6. Nightmares and The Painting

Chapter 6 : Nightmares and The Painting

Ruby return to her dorm with a jar of cookies she got from Ms. Glynda. Her team mates aren't here. Perhaps they're still in class. Ruby is given a permission from Ozpin to skip class. She set herself at the edge of her sister's bed. Munching a cookie in her mouth, she notice a picture on her sister's desk.

It's a picture of her and Yang. She can't recall when they took the picture but maybe a long time ago. Lately, she's been avoiding her sister. A pang of guilt hit her in her chest. She wanted to tell her what exactly happen. But will her sister accept her or avoid her?

Suddenly, the door of her dorm slammed open and stood Yang with teary eyes. Yang didn't notice Ruby is watching her, sit and pulled her knees and hug them. "Yang, why are you crying?"

The blonde open up her hands, still crying. Seeing her sister before her, she pull her into a tight embrace.

* * *

Weiss is sitting on a bench at the academy's park. Cold breeze gently hit her face. Her kind is thinking of Ruby and the painting that Yang told her.

_"Weiss, do you know about the painting at the hallway of our dorm?" Weiss wondering what painting that Yang mentioned. "You mean the 'Moon Goddess' painting?"_

_"Moon Goddess?"_

_"Legends says that every full moon, the Moon Goddess will land on Earth and abducts anyone she sees."_

_"Is that possible?"_

_"Nah, it's nothing more than a myth. Just like the myth of were-Grimm."_

_"Were-Grimm?"_

_"Just like werewolves, they transform during full moon. But they also can turn by injuring themselves. Like I said, it's just a myth. So there's nothing you should believe about it..."_

'But Ruby disappear every full moon. And there's a cut on her palm. Could it be...?"she thought. She didn't realize that Blake stood in front of her. She shrieked,"God, Blake! Stop doing that!"

"Hey, I keep calling you but you ignore me," the Fauna crosses her arms. Weiss blush in embarrassment, shift herself a bit to give her some space.

"What's on your mind, princess?" The heiress look down. She mutter,"Ruby..."

"What's wrong?"

"Do you know about the Were-Grimm myth?" The Fauna nods." It's just like the myth... Ruby disappear every full moon. Plus, we found a cut on her palm yesterday, no?"

"So you suspect Ruby is a were-Grimm?"

"I don't know, Blake. It's just... everything's weird. Ruby started to avoid us even her sister. I just can't think of anything else..." Weiss sigh.

Blake put her hand on the heiress's shoulder and give her an assuring smile. The heiress return her with a small smile.

* * *

An awkward silence take over the room. The tense between Yang and Ruby make the situation even awkward. Neither of them dare to held a conversation.

Ruby keep enjoying her cookies. Yang's thinking a perfect word to tell her littles sister. She keep glaring her sister who enjoying her cookies too much.

"Why are you crying just now?" Yang startled. Ruby keep munching on her sweets. The blonde tried to answer her question. Too late, the huntress continued,"Is it because that you heard I'm dying?"

Yang's speechless."H-how do you...?!" "I heard you, sis. There's no need to hide it from me. You cried because you fear that you'll lose me."

"Ruby, I'm sorry. I didn't mean to..."

"No. I'm the one who should be sorry. I'm sorry for not telling you the truth. I'll tell you but not now. Although I keep avoiding you, I'm the still the same old Ruby you know. I promise I'll tell you guys everything."

Yang is still speechless. However, she's glad that there's nothing wrong with her sister. If it's true that she'll tell her secret, she won't mind waiting at all." My baby sis is alright!"she says as she pull Ruby in a suffocating hug.

"Ow, sis! Let go of me! YANG!"

* * *

She feel so cold. She feel...lonely. Her surrounding is dark and cold. Slowly, it started to get brighter. What she sees is unacceptable.

She sees her friends, bleeding to death. Weiss and Blake lie on the cold snow. She try to call them but she can't. She can't even speak nor move. She stood there, unable to do anything. Not far from her she saw Yang fighting a Grimm. She's fighting with Ruby, Grimm Ruby.

Her sister badly wounded, not realizing that the Grimm is actually her little sister. She try to reach her but she slowly distant away from them. The more she try to reach, the further she's away from them. But she's too late. The Grimm clawed her sister in the gut. Blood spatter on the floor. Her sister fall like a lifeless rag doll. The Grimm was about to devour her and Ruby scream at the top of her lungs."NOOOOOOOOOOOOOOOOOOOOOOO!"

"Ruby! Ruby, wake up!" The voice of her sister manage to wake her. Ruby open her eyes, tears roll down her cheeks. She hug Yang tightly. Yang hug her back and shush her,"Shhh, it's okay. It's just a dream. I'm here."

"Yang, I'm scared. In my dream, I-I killed you... I-it was cold a-and dark a-and lonely... I saw Weiss and Blake d-die and-and..." The blonde put her finger on her sister's lips. She caress her hair gently. Looks like she's not the only one who had a bad dream.


	7. Secret Reveal

**I took an anime reference and inserted it here. Do you know what it is?**

* * *

Chapter 7 : Secret Reveal

Things begin to return to normal. Ruby is often seen with Yang. Weiss and Blake are relief. Although Yang is overprotective sometimes, the huntress appreciate the attention given. Ruby is much happier than before.

The girl in red realizes she need to tell her sister sooner or later. Still, she wanted to enjoy the rest of her life, for Yang's sake. Ruby is on her way to her dorm but she stopped before the 'Moon Goddess' painting. She gaze upon the woman in the white dress," Luna, this charade will soon over. I have no choice but to reveal my secret. I don't want to make my sister worry anymore..."

"Yo, Ruby!" She turn to her left and saw her sister walking towards her with her arms folded behind her head. "Oh, hey sis."

"I thought you're at the cafeteria so I was looking for you there."

"Sorry, I wanted to finish my assignment that Ms. Glynda gave me."

"Do you need my help? I'm kinda bored right now."

"Sure, thanks sis!" Ruby gave her sister a big smile before she left to her dorm. Yang stood in front of the painting and look at it,"Creepy... Feels like she's watching..."

* * *

Team RWBY was assigned to the Snowy Forest again. Weiss keep complaining for not getting a beauty sleep and Yang keep nagging about Ruby's safety. Upon arriving at their location, Ruby's hair begin to rise. Yang started to get worried.

The forest is silent as usual. The four of them are currently on guard. Ruby aimlessly walk deeper into the forest with her hair still rising. Blake realizes her sudden change in behavior, follow her.

They reached at the clearing of the forest. Ruby's hair rise wildly. A howl is heard in the darkness. A pack of Beowolves appear from the forest, surrounding the girls. The huntress begin to growl and so does the wolves. She point Crescent Rose towards them. Her hands twitching and her growl grew louder, threatening the wolves. The other three watch in amazement as the wolves slowly retreating.

Suddenly, a large Beowolf pounce Ruby and the smaller ones started to make their move. Yang's focusing to much to protect her sister didn't realize a wolf was about to claw her but Blake managed to kill it. Ruby is struggling to fight the Alpha. Firing and slashing are not enough to kill it. She later join the others to fight the goons.

More and more Beowolves appear from the forest. The girls realize they're outnumbered. The Alpha stare at Ruby into her eyes. Ruby feel more aggressive than before. The Beowolf is challenging her. 'It's almost the time...' she whispered.

"Guys, if I ever tell my secret, are we still friends?" They're shocked. This is it... "O-of course we are! Why would you say something like that?!" Weiss stuttered. Ruby smile. "That's all I want to know."

Ruby dropped her scythe and lunge herself towards the Alpha. Yang was about to grab her cloak but it's too late. Full moon appeared from behind the clouds. Ruby's eyes turns animalistic yellow, grew fangs and claws on her hands. Her hair grew slight longer and furry. Her clothes somehow binds with her body. Her cloak remains the same. She pounce on the Alpha and clawed it in the face.

The three girls watch in awe. They're speechless to say anything. Seeing an unbelievable thing before their eyes. "Ruby is a Grimm?!

* * *

**Have you found out what it is? State your answer in the review :D**


	8. Howl of Sadness

Chapter 8 : Howl of Sadness

Ruby tried to claw the Grimm in the gut but the goons surrounded her and made her harder to move. She drowned within the Beowolves, her only target is the Alpha. Yang activate her Ember Celica and charged herself to the Grimms, assisting her sister. Weiss and Blake join in the fight too.

Yang fired her shotgun to the goons which clings on her sister. Ruby take the chance and lunge herself at the Alpha. She keep clawing it but the Alpha clawed her on her side. She release a roar of pain. Weiss distracted the larger Grimm from attacking Ruby. Yang and Blake prevented the goons from reaching them.

Ruby need to make her strike count, either on the head or the gut. The larger Grimm was fully distracted by Weiss. She took the chance and plunge her claws into its head. The creatures's blood cover her paw. The smaller wolves slowly retreating. Ruby gave out a threatening roar. The Grimms later flee into the forest.

Before Yang could ever say anything, Ruby grab the three of them and put them on her back. She immediately left from the clearing. She head to a cliff side. Upon arriving, she dropped them off and walk away from them. At the cliff side stood a tombstone. Ruby walk towards it and bowed her head.

"Ruby, is this the secret that you want to tell us? You're a... Grimm?" The Grimm glance at her sister. She wouldn't dare to look at her friends. She lie down and curled herself. Yang slowly approach her. She gently caress her sister's fur. Ruby open one eye to look at the blonde. "It's okay, Ruby. Even though you're a Grimm, you're still our friend. My sister. I won't abandon you."

Ruby raise her head slightly. Weiss and Blake caress her fur along with Yang. " Really? You won't...?"she said. The heiress and the Fauna nodded. Yang hug her sister who appeared to be a lot bigger than herself. Ruby nuzzled in her sister bosom. Weiss giggled and Blake smile.

"Should we head back? Or stay here for tonight till the end of full moon?" says Weiss. "We'll stay here for tonight. Everyone in Beacon will freaked out when they saw Ruby." Blake rolled her eyes.

"That settles it! I'll take the paws!" Yang run into Ruby's paws and nuzzle into her sister's neck. Weiss begin to pout,"No fair! I wanted that spot!" "Nuh uh, princess! I booked it first! So it should be my spot!"

"No you didn't!"

"Oh yes I did!"

"Guess I'll take the tail..." Blake smiled on the two girls. After few minutes of childish fight, Weiss and Yang share the same spot while Blake sleep at Ruby's tail. The Grimm feel a slight relief that her friends didn't mind of her being a Grimm. For the first time, Ruby have a peaceful slumber in her life.

* * *

The next morning, Ruby hasn't return to her human form yet. Sun started to rise from the East. The four of them stood before the altar. "Summer Rose. Thus kindly I scatter..." Yang whispered.

"Ruby, is this your mother's...?" Ruby nodded. She gave out a howl. But this howl is not just any typical howl. It's more painful and sad. Even Yang feel her pain. As dawn comes, Ruby slowly return to normal. Her fur slowly grew shorter. Her body grew slight smaller. Her yellow eyes turn into silver. By the time she return to normal, she collapse in the snow. Yang panicked but Blake say,"Don't worry. She just exhausted." Yang sigh in relief.

"Gosh, she keep making me worried!" The blonde exclaimed. She carry the huntress on her back. Somehow, she felt her sister is a bit smaller than before. "C'mon, we better move."

"Aww, do we have to walk?" "Stop whining, princess. All of us need to walk, too." Weiss huffed and look away. Sun has rise and lighten the forest, leading them to Beacon.

* * *

"Where have you girls been?!" Ms. Glynda and Professor Ozpin waiting for them at the academy's entrance. "Uh..we were..." Yang stuttered.

Professor Ozpin notices Ruby on Yang's back,"Bring her to my office. And I need to talk to the three of you," he said. Yang, Blake and Weiss look at each other but no one protest. The trio follow Professor Ozpin to his office.

Yang set her sister on a couch and draped a blanket reaching her shoulders. Ms. Glynda served them some coffee. "So you've seen it, don't you?"

"You knew?!" Weiss exclaimed. Both Glynda and Ozpin nodded. Blake and Weiss look at each other. Yang remain silent, waiting for more information from the man. "As you can see, Ruby has the ability to shifting herself into a Grimm. A Fenrir to be exact. She's been undergoing these changes for a while. You do realize that she disappear every full moon, yes?" "True, but..."

"First of all, I wanted to apologize for not telling you three about this. We wanted to but Ruby insists to keep it secret and she'll tell you herself. Turns out she decided to show it."

"Professor, h-how could this happen...?" The only question that Yang been eagerly to ask. She's curious how her sister possessed such ability.

"She's not actually a Grimm. She was...experimented..." Yang is speechless. Her lilac eyes turns red. She activated Ember Celica. She tighten her hands into fists. Blake hold her shoulder and calm her down. She deactivated her gauntlets but her eyes remain red and her fist tightened.

"I understand how upset you are. We don't know how they got their hands on her. Investigation were held to capture them but no luck. Right now, all we have to do is keep her safe. Who knows that they'll find her and...only god knows what'll they do to her..." Yang glance at her sister who's sleeping peacefully on the couch. The girl who's been her sister and a friend for a long time. There's no way she'll let anyone touch her. She swear that she will protect her no matter what happens.

* * *

Blake's already asleep but Weiss couldn't. She couldn't close her eyes even though she feel tired. Yang enters the room with Ruby in her arms. She set her sister next to Weiss. The heiress draped her blanket on the girl. She gently caress her hair. "Do you think they'll find her?" Weiss ask. Yang lift both of her shoulders.

"Who knows, Weiss. All we have to do now is to keep her safe. We need to keep an eye on her from now on," the blonde says. She sit at the side of the bed. Seeing her sister sleep making her happy. "Y'know, you look more like a mother than a sister to me."

A small shade of red appeared on her cheeks. She coughed a bit and says,"D-don't be silly! I just do it because I care! S-so don't make any speculations!" Yang look away, still blushing. Weiss giggled. She look at Ruby and secretly planted a kiss on her forehead. Ruby smile in her sleep. Yang gets up and head towards her bed. "Goodnight, princess."

"Goodnight, Yang." She lie down on her pillow. Slowly, she pull Ruby into an embrace. The huntress appear to be smaller than before. Before she close her eyes, she whispered,"Goodnight, my sweetheart..."

* * *

**This is the longest chapter I've written. I feel something wrong with it :/ . Anyway, criticism are always welcome (as long it's not a spam).**


	9. Mysterious Doctor

Chapter 9 : Mysterious Doctor

Ruby is forbidden from leaving her room nor her bed. Yang makes sure she won't escape by sitting next to her. Her actions sometimes irritating but she's her sister, what can she do about it?

Blake and Weiss often visit the girl after their classes ended, though only for a while. Yang was excused from classes and trainings in condition she need to finish her assignment given in the future. Although Ruby already recovered from her wounds, Yang insisted her to stay in her room unless she says so.

After a few convincing to her sister, Ruby is allowed to go outside if Yang or Weiss or Blake tag along. In the academy's garden, the huntress is seen chasing a butterfly in her semi-Grimm form. As she was about to pounce the butterfly, Yang caught her tail, "Easy there, little sister. You have to watch where you going."

"Aww, c'mon! I'm just chasing the butterfly. I won't wander far," Ruby gave her sister a puppy pout. Yang, unable to resist the girl's big, shining eyes, let go off her tail. Ruby continued to chase the butterfly. The blonde heard a rustling at the tree she sit under. Above her is Blake. The Fauna seems to be watching them all the time. "Don't you think that Ruby seems a bit smaller than before?"

"Well, she said it happens every time after her transformation. But she'll turn normal within few days," the blonde says. She keep her eyes on her little sister as she leaping around, trying to catch the flying insect. Blake couldn't help but smile. Lately, Yang being overprotective towards her sister. She rarely seen her wild side. Now, she's a gentle and caring mother. The Fauna is able to see the soft side of her friend.

She drop herself from the tree branch and sit next to Yang. She can't help but ask, "Is it okay for Ruby in that form?" "Professor Ozpin said that he'll try to cover her up," The blonde replied. Ruby begin to roll herself on the grass. Yang called out her sister but she ignored it. The girl huffed and pouted. Blake giggled. "Don't you think you should give your sister some space?"

"Hope I could, Blake. By the way, where's Weiss?"

"Speak of the Devil, here she comes," Blake pointed at Weiss who's approaching Ruby. Both the Fauna and the blonde heard Ruby's laugh as the heiress tickle the girl. Blake and Yang smiled,"Those two are perfect together," Blake says. Yang look at the Fauna and say,"What are you trying to imply here?"

"Admit it, Yang. You too think that they're look cute together." Yang sigh but she smiled. She couldn't help but admit it, "Alright, they are... It's only a while but they seem to grew closer than before."

"You okay with it?"

"Hey, as long as my sister happy then I don't mind at all." Blake smiled and leaned her head onto Yang's shoulder. The blonde blushes. Weiss and Ruby are still playing. Things never been so peaceful before. Morning breeze blew through her. She heard a soft snoring next to her. She pray that this moment will last forever.

* * *

Ruby, Weiss, Blake and Yang take a trip to the city to buy some school supplies. The city is crowded like sardines. Ruby keep wandering off from the group and Yang keep tugging her cloak. The huntress mumbled to herself, upset that she's unable to go to the bakery. Few moments later, they arrived at a bookstore.

Blake and Weiss head to the history section while Yang and Ruby head to the medical section. Suddenly, Ruby's hair rise upon seeing a man in a lab coat. She quickly hide behind her sister, making Yang confused. "What's the matter, little sister?" She didn't reply. Instead, she released an animalistic grunt.

The man in the lab coat looked around to find the source of the grunt. His eyes then locked onto the girls. He closed the book he read and approach them, "Hello, miss. Do you know where the strange sound is coming from?" he asks.

"Oh, it's from my sister here," she says and showed him Ruby but the girl immediately hide behind the blonde. Secretly, the man glare at Ruby and she tried to avoid his sight. "Is she okay?"

"Ah, she's not familiar with strangers. Please excuse her..." She felt a tug on her shirt. Ruby's hair kept rising and her eyes shows great fear. The man excused himself. As the sight of the man gone, Ruby let go of her sister's shirt and her hair started to fall. The huntress managed to calm down.

"What's with you, Ruby? Why did you acted like that?"

"I don't know. I just...hate him." Yang sigh. She can't blame her sister. Maybe she's traumatized, she thought. After grabbing some medical books, they later meet up with Weiss and Blake. Ruby is still wondering about the man,"I think I've met him but...where?" she mutters.


	10. Trap

Chapter 10 : Trap

"Girls, I have an assignment for you!" Ms. Glynda Goodwitch barged into their dorm and startled them. Ruby climbed on a chandelier and hissed. Yang fall from the couch and landed on Blake. Weiss dropped her book and squeaked. "Professor Glynda! You startled us!" said Ruby from the chandelier.

"Sorry, girls. As I said, you have a new assignment." Ruby dropped herself from the chandelier and safely landed on a couch. Yang immediately gets up on her feet and helped Blake. Weiss later joined the trio, "What's the mission, professor?" Blake asks.

"A man by the name of Doctor Alex need you girls to investigate his laboratory. He claimed that strange activities occurred for the past few days and wanted it to be exterminated..." Ruby's hair rise all of sudden and started to hisses. Fear are shown on her face. She immediately scurried behind her sister and hisses again. "We will investigate the laboratory, professor," the Fauna said. The woman nodded and excuse herself.

Ruby's hissings lowered and her hair falls. She started to calm down. Yang patted her little sister's head gently. She purred and nuzzled herself into the blonde's palm. Blake and Weiss giggled. They forgot about the questions they wanted to ask.

* * *

In the north of Vale lies a dome-shaped building, appeared to be deserted for long. The girls arrived at the entrance of the building. Ruby begin to have suspicions, "Guys, I don't think we should go in there..."

"Ruby's right. This building seems abandoned for a long. And there's no sign of anyone been here," Blake inspected the ground. Yang and Weiss hesitated. Ruby started to get worried. Slowly, the heiress opens the door. The insides are dark and cold. The four of them readying their weapons. They walked into the lab. Suddenly, the door slammed shut and the lights shone on the girls. A group of men surrounded them. A clap echoed from a distance.

The same man in lab coat that Yang and Ruby met at the bookstore. Ruby suddenly backed off. The man who named Alex glares at the huntress. She hide behind her sister. With his devilish grin, he say,"Welcome, children of Beacon. First of all, I would like to thank you for bringing our lost specimen."

"Specimen? What do you mean by... Oh no." Yang looked at her sister who tremble in fear. Doctor Alex glares her with an evil smirk on his face, manage to bring fear into the girl. Ruby is speechless. Unable to accept that the man found her. She dropped Crescent Rose. The weapon and the floor collided, making an eerie sound. "H-he's the one who e-experimented me... He s-said that I'll l-live in a b-better life with my m-mother. But I... I..." Suddenly she screamed. A vision of her dead mother appeared in her mind. Yang turned to look at Doctor Alex. Her lilac eyes turned red. She activated Ember Celica and about to punch him. But one of his men pointed his gun on Ruby. "Ah-ah-ah! I wouldn't do that if I were you. One step and she'll die," he said with a smirk.

Yang hesitated. Blake and speechless. Doctor Alex plucked his finger and Ruby is taken away. Yang tries to chase them but she was blocked by Alex. "Not so fast, blondie. I got a special cell for you three." With a smirk on his face, he turn away from them.

* * *

"DAMMIT!" Yang punched the cell wall with her bare fist. She keep punching and injuring her hand. Weiss tried her best to comfort the blonde but to no avail, she won't listen. Blake tries to find a way out but no luck. Their weapons right outside their cell, Ember Celica, Gambol Shroud, Myrtenaster and even Crescent Rose.

Yang stopped punching. She dropped on her knees and cried. Blake couldn't stand seeing the blonde cry. She pulled her into a hug. Yang nuzzled her face on her neck and cried. Blake blushes. Weiss look outside their cell and found out the cell bars are rusty. Slowly, she break one by one of the bars. She later created a large gap between the bars, enable them to escape. "Guys, look! I've made the exit!"

Yang look up and saw the gap that the heiress made. She wipe her tears and stood on her feet, followed by Blake. They get out of their cell and grab their weapons including Ruby's. Weiss put Crescent Rose at her waist. Without any hesitation, they leave the dungeon to look for their teammate.


	11. Escape

Chapter 11 : Escape

They checked every cell they stumbled across, but Ruby is nowhere to be found. They go to the next floor. They checked most of the cells on the floor but there's a cell that caught their attention. BEO A27 are stated on the door. "You think this is it?" Weiss said.

"One way to find out," Yang said. She activated Ember Celica and punched the door. The door fly inwards. The room is dark and damp. They could smell blood inside. The wall were smeared in blood. Weiss cover her nose with her hand. Skeletons and organs are scattered on the floor. Suddenly, a splotch is heard and Weiss squeaked, "Eek! I-I think I stepped on it!"

Her pure white boots are covered in blood. The thing she stepped was an intestine. The three of them covered their nose with their hand. As they walk deeper, the stench of blood is getting stronger. A sound of human breathing is heard. Then, a sound of metal colliding echoed in the room. Yang tried to find the source and stumbled upon a figure. A small red figure is seen from a distant. They immediately walk towards it, carefully find their step in the pile of organs.

As they reached the figure, they gasps in horror. It was Ruby, who covered in blood and chained. The girl slowly lift her head. A cold, dark eyes watching her teammates before her. A small smile formed on her face. She stuttered, "I-I knew you guys w-would come..."

Yang couldn't hold herself and hug her little sister. She could feel her cold skin and her trembling hands behind her. Oh how terrible she's in! She let go of her sister. Ruby looked paler and weaker than before. Blake cut the chain with Gambol Shroud. The huntress tries to get on her feet but in her current state, she couldn't even stand properly. Weiss and Yang support her by holding her arm. Suddenly, a siren and red lights blinking, alerting the guards.

Yang quickly carry her sister in bridal style. After they left the room, a group of men started to chase them. Weiss try to delay them by casting ice wall. The ice wouldn't stand long with the weight of the men. Not knowing where they going, they randomly enter a room and decided to hide. The blonde set her sister on the floor. Ruby shivers in cold and weak.

Suddenly, white lights shine brightly on the girls. The place appeared to be like an arena. Yang hold her sister tightly. Then, a man's voice is heard on an altar, "Congratulations on finding our testing arena. Lets play a game, shall we? The rules are simple. If you manage to defeat me, I'll let you go. But if you don't, then I'll just kill you."

Doctor Alex jumped from the altar in his Grimm form. The three of them are shocked. "Surprised, are we? I, too, possessed this type of ability. To be exact, I'm the first specimen." he said.

"Then, why you used Ruby as your lab rat?! What does she have to do anything with it?!" Yang shouted. Her lilac eyes turn red.

"If this worked on adults, why not children? Before we ever met her, we used countless of children as out lab rat. But all of them are failure. Then, we found Ruby. It's easy to manipulate her mind. So we used her. My, she's the brightest specimen we ever had. The experiment was a success until she begin to resist. She was out of control that time. We chained her and feed her with human fleshes. Still, she manage to escape after what we did to her. Tsk, tsk, heck, she even killed her own mother."

Ruby's eyes wide open. She slowly stood on her feet. Yang tries to help but she refuses. The huntress walk toward the Grimm, facing him with angered eyes, "You're the one who said that I'll live in a better life. I would become a great huntress in the future. Instead, you used me. What are your purpose exactly?!"

"Ruby, dear. My purpose is simple. To eliminate the humans and let the human-Grimm hybrid rule the Earth. From my research, Grimm exists because of the darkness in human's heart. If I ever eliminate human races, Grimm shall ceased to exist and us, human-Grimm will live for eternity!"

"You are no god to change the fate of the world! You have no rights to change nature!" Grimm Alex turn towards Weiss. The heiress backed off. "Dear, princess. I can do anything once I get my hands on the humans and Dust. And you might join me, Ruby. A bright future is ahead of you," he say.

"NO! I have enough with your lies! You turned me into a monster and a murderer! And I have no reason to deceive my friends!" "So be it."

Grimm Alex was about to swipe his claws on Ruby when suddenly she turned into a Grimm and pounced him. The size of her Grimm is much bigger than before. Her yellow eyes turn crimson. A battle between Grimm has begun.

* * *

**I forgot to mention that Alex's Grimm form is a Beowolf =3**


	12. Grimm Battle

**I sucks at writing battle scenes XP. Anyway, enjoy! :D**

* * *

Chapter 12 : Grimm Battle

Two Grimm are fighting in life and death match. A match to determine who are worthy enough to live. Ruby is trying her best to claw either his head or his heart. The two killing machines colliding with the walls. Pieces of the building crumbled and fall to the ground. Yang, Weiss and Blake immediately dodge them.

Yang wanted to jump into the fight but Blake reluctant to let her,"What the hell, Blake?! We need to help her!" the blonde protested.

"Don't you see how fierce the fight is?! If you jumped in, you might get killed! I'm sure Ruby wouldn't want that!" Yang looked at the two Grimm. Ruby keep on aiming Alex's heart but to no avail, he kept dodging. What Blake said was true, however, she wanted to help her sister somehow. Then, an idea came up into her head.

"Why don't we distract him? That way, Ruby could claw him in the gut!" she said. Blake and Weiss nodded.

Alex pinned Ruby on the ground, readying his claw. As he was about to plunge his claw, Yang fired her gauntlets on his face. His sight is locked on the blonde. He gets up but couldn't move as his legs are covered in ice. Ruby took this opportunity to plunge her claw into his chest, pulling him out from his Grimm. The body perish in thin air and Ruby smashed him on the ground. She gave out a roar and frightening the doctor. "P-please... S-spare me..." he begged.

"Oh, we'll spare you alright. If you survive in jail!" Ruby let go of him. Blake tied him up with a rope she found. Yang and Weiss look at their Grimm teammate. She released a whimper and lowered her head. The blonde stroke her fur, followed by Weiss. "It's okay, Ruby. You're not a monster. Just remember that," Yang said.

Ruby raised her head. Her crimson eyes turn into silver. Happiness are shown in her face,"You guys don't mind at all?" The Grimm said. The three of them nodded. Suddenly, she licked her friends, causing them covered in saliva.

"Ew, Ruby! Now I need to bathe 10 times a day!" The heiress shrieked. Yang and Blake chuckled. Yang looked up at her sister. She patted her face gently," C'mon, let's go home."

"What about him?"

"We'll just turn him in to the police. They know what to do."

Ruby lowered her head to allow them to get on her. She carry Doctor Alex in her mouth. She sprinted out from the building and just in time, it collapsed. Yang demanded to return to Beacon immediately. A final glance on the collapsed lab, she run into the direction of the academy.


	13. Epilogue

**This is the third time I update this chapter :/. Gosh, it's so hard to write! And please don't judge me! X(**

* * *

Ruby is seen stood in front of the painting. Though the full moon doesn't affect her anymore, her interest on the painting didn't change. She sometimes feel like its watching her but she think it's only her imagination.

Suddenly, Yang called her out not far from her. The golden hair girl approach her with a huge grin on her face. Ruby smiled. "Hey, we were looking for you."

"Sorry, just looking at this painting for the last time." Yang glance on the painting and turn to look at her little sister. The blonde try to change the topic.

"Oh, Weiss baked a strawberry pie for you. Why don't we go to the dorm?" Ruby immediately turn to her sister with a big, shiny eyes. She begin to drool over the sweetness of the pie. Yang shook. "C'mon, we'd better hurry before someone else eat it!"

Yang ran ahead before her. As Ruby was about to chase her, her right hand suddenly become a claw. She frozen and eyes wide open. She quickly return it to normal. She feel pain in her chest. An urge to kill...her sister. She shook her head, trying to throw away such thoughts.

Seeing her sister waving to her, she ignore the pain in her chest and sprinted towards her. Not far from the painting, Professor Ozpin stood there with a bunch of documents in his hand. He mutter, "Ruby Rose, BEO A27. Status... Incomplete..."


End file.
